Nanodiamond and a method for the production thereof

ABSTRACT

The invention relates to carbon chemistry and is embodied in the form of a nanodiamond comprising 90.0-98.0 mass % carbon, 0.1-5.0 mass % hydrogen, 1.5-3.0 mass % nitrogen and 0.1-4.5 mass % oxygen, wherein the carbon is contained in the form a diamond cubic modification and in a roentgen-amorphous phase at a ratio of (82-95):(18-5) in terms of a carbon mass, respectively. The inventive method for producing said material consisting in detonating in a closed space of a carbon-inert gas medium a carbon-containing oxygen-deficient explosive material which is placed in a condensed phase envelop containing a reducing agent at a quantitative ratio between said reducing agent mass in the condensed envelop and the mass of the used carbon-containing explosive material equal to or greater than 0.01:1 and in chemically purifying by treating detonation products with a 2-40% aqua nitric acid jointly with a compressed air oxygen at a temperature ranging from 200 to 280° C. and a pressure of 5-15 MPa.

This application claims the benefit of PCT/RU2005/000686 filed Dec. 30,2005, which is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

The given invention refers to the field of inorganic chemistry ofcarbon, to be exact, to diamond modification of carbon-Nanodiamond,possessing qualities of ultrahard material and method of its production,in particular, a method using detonation synthesis fromcarbon-containing explosive mixed with further Nanodiamond extractionusing chemical methods.

PRIOR ART

Various composition materials produced by methods of detonationsynthesis from carbon-containing explosives and containing carbon invarious phases are known. Nanodiamond is formed at detonation ofcarbon-containing explosives with negative oxygen balance in specialconditions in environment allowing to preserve it. Nanodiamond is anindividual particle from 2 to 20 nm in size, utilized, as a rule, inbigger particles ensembles. Due to its nanosize Nanodiamond possesseshigh dispersion level, defects of surface structures particles, andconsequently, active surface. These characteristics may vary in quitewide ranges depending on Nanodiamond production conditions.

Experts in the field of carbon chemistry are well aware for almost 20years about Nanodiamond of classical elemental composition, mainlycontaining carbon in cubic diamond phase with the following elementsstructure, mass. %: carbon—72-90; hydrogen—0.6-1.5; nitrogen—1.0-4.5 andoxygen—4-25; and methods of its production (Volkov K. V., Danilenko V.V., Elin V. I. Diamond synthesis form carbon VV detonation products,Burn and explosion Physics, 1990, t. 26, No 3, p. 123-125; Lyamkin A. L,Petrov E. A., Ershov A. P. and others. Diamond acquisition fromexplosive materials, DAN USSR, 1988, t. 302; p. 611-613; Greiner N. R.,Phillips D. S., Johnson F. J. D. Diamonds in detonation soot, Nature,1988, vol. 333, p. 440-442; Petrov V. A., Sakovich G. V., Brylyakov P.M. Diamonds keeping conditions at detonation, DAN USSR, 1990, t. 313, No4, p. 862-864; V. Y. Dolmatov. Superdispersed diamonds of detonationsynthesis: characteristics and use, Chemistry progress, 2001 t. 70 (7),p. 687-708; V. Y. Dolmatov. Superdispersed diamonds of detonationsynthesis, St. Petersburg, SPbGPU, 2003, 344 p).

The properties of classic Nanodiamond are fully described. (V. Y.Dolmatov. Superdispersed diamonds of detonation synthesis:characteristics and use, Chemistry progress, 2001 t. 70 (7), p. 687-708;V. Y. Dolmatov. Superdispersed diamonds of detonation synthesis, St.Petersburg, SPbGPU, 2003, 344 p; EP, 1288162, A2,).

Carbon chemistry experts are aware of the condensed carbon(CC)—composition carbon material, containing carbon in variousmodifications and, depending on conditions of detonation ofcarbon-containing explosives containing or not containing carbon incubic diamond phase. Such CC can be produced by detonation ofcarbon-containing explosives with negative oxygen balance in specialenvironment under conditions allowing to preserve condensed carbonproducts of explosion. (Lyamkin A. I., Petrov E. A., Ershov A. P. andothers. Diamond acquisition from explosive materials, DAN USSR, 1988, t.302, p. 611-613; Greiner N. R., Phillips D. S., Johnson F. J. D.Diamonds in detonation soot, Nature, 1988, vol. 333, p. 440-442; PetrovV. A., Sakovich G. V., Brylyakov P. M. Diamonds keeping conditions atdetonation, DAN USSR, 1990, 1.313, No 4, p. 862-864; V. Y. Dolmatov.Superdispersed diamonds of detonation synthesis, St. Petersburg, SPbGPU,2003, 344 p V. Y. Dolmatov. Superdispersed diamonds of detonationsynthesis, St. Petersburg, SPbGPU, 2003, 344 P).

It is known that CC production method may include blast ofcarbon-containing charge in various environments, for example:

-   -   in gas environment, inert to carbon, for example in nitrogen        environment, carbonic acid, light-end products of previous        blast. (U.S. Pat. No. 5,916,955, CI);    -   in water foam (Petrov V. A., Sakovich G. V., Brylyakov P. M.        Diamonds keeping conditions at detonation, DAN USSR, 1990, t.        313, No 4, p. 862-964);    -   charge water irrigation (RU, 2036835, CI);    -   in water cover (U.S. Pat. No. 5,353,708, CI);    -   in ice (RU, 2230702, CI).

Out of all existing methods of carbon-containing explosive materialsdetonation, the most effective from the view point of CC and diamondmodification output is charge blast in water or ice cover (V. Y.Dolmatov. Superdispersed diamonds of detonation synthesis, St.Petersburg, SPbGPU, 2003, 344 p; RU, 2230702, C).

The CC received is a nano-dispersed carbon-containing powder, possessingspecific characteristics and structure. For example, CC is distinguishedby high dispersion ability, wide specific surface, presence of newlycreated carbonic faulted structures, increased reactivity.

There is synthetic diamond-carbon-base material (U.S. Pat. No.5,861,349, A), consisting of grouped round and irregular shapedparticles in diameters diapason not exceeding 0.1 M, where: a) elementcomposition of mass. %: carbon from 75.0 to 90.0; hydrogen from 0.8 to1.5; nitrogen from 0.8 to 4.5; oxygen—up to balance; b) phasecomposition, mass. %; amorphous carbon from 10 to 30, cubic modificationdiamond—up to balance; c) material porous structure, the volume of pores0.6-1.0 sm³/gr; d) material surface with existence of over 10-20% ofsurface of throwing, nitrite, primary and secondary hydroxyl groups,possessing various chemical shifts in the field of NMR spectrum and oneor more oxy carboxylic functional groups, selected from the group ofconsisting of carbonylic groups, carboxylic groups, guanine groups,hydroperoxide and lactones groups over 1-2% of material surface relatedto carbon atoms by noncompensated connections; and e) specific surfacefrom 200 to 450 gM²/g.

Above mentioned material is produced by detonation synthesis method inthe closed volume of explosive charge, which mainly containscarbon-containing explosive material or mix of such material, possessingnegative oxygen balance. The charge detonation is initiated in presenceof carbon particles with concentration from 0.01 to 0.015 kg/m³ inenvironment, consisting of oxygen from 0.1 to 6% in volume and gas,inert towards carbon, at temperature of from 303 to 363 K. (U.S. Pat.No. 5,861,349, A). This method is carried out in pressure chamber withcharge of negative oxygen balance, consisting mainly of, at least, onecarbon-containing solid explosive.

10-20% of material surface are occupied by metal- nitrile-, primary andsecondary hydroxyl groups and also oxycarboxyl and functional groups ofgeneral formula O.dbd.R, where R— is .dbd.COH, .dbd.COOH,.dbd.C.position 6H. position.4 or other combinations, besides 1-2% ofmaterial surface is occupied by carbon atoms with noncompensatedconnections.Parameter−lattice distance−is a₀=0.3562+0.0004 nm, content ofnonflammable impurities is from 0.1 to 0.5 mass. %.

The x-ray amorphous phase of the received material does not containgraphite.

Oxygen-containing functional groups, as a rule, are derivatives ofvarious surface carbon structures, including aliphatic, alicyclic andaromatic. Both lacton.dbd.COOCC⁻, quinine.O.dbd.C pol. 6H.pol.4H.dbd.O,and hydroperoxide.dbd.COOOH groups were identified on surface of theproduced material. Total quantity of oxygen-containing surface groupstakes from 10 to 20% of sample surface.

However, the above mentioned method of diamond-carbon materialproduction has low output of diamond-carbon material—3.1-5.1 mass. % anddoes not allow to receive material with high efficacy and of highquality, as due to low content of carbon—the most important element indiamond-carbon material—the end product contains large quantity ofheteroatom, mainly oxygen, existing in form of lactone, etheric andaldehyde groups that leads to excessive chemical activity ofdiamond-carbon material. This fact increases possibility of destructiveprocesses in compositions with use of diamond-carbon material, e.g. inpolymerous and oil compositions, especially at elevated operatingtemperature.

Low (from 9.1 to 58.4 mass. %) content in produced condensed carbon ofthe main component of Nanodiamond—cubic modification diamond—makes thefollowing chemical refinement of Nanodiamond complicated. Moreover,Nanodiamond properties are worsening due to considerable, ˜2.3 mass. %,quantity of nonflammable impurities in chemically refined Nanodiamond.The above mentioned patent (U.S. Pat. No. 5,861,349, A) shows only onemethod of material production using one composition of explosive—mix oftrotyl and cyclonite with 60/40 ratio respectively. This does not allowto evaluate all advantages of above mentioned method of diamond-carbonmaterials production. There is Nanodiamonds, produced by detonationsynthesis, refinement method, with following impurities refinement (RU,2109683, A) using two-stage treatment of detonation products by watersolution of nitric acid: first 50-99%-nitric acid at 80-180° C., then10-40%-nitric acid at 220-280° C. Liquid phase behavior of the processis provided by pressure. However this method is not used widely due tohigh aggression and corrosion activity of used concentrated nitric acid,its large consumption, complicacy of utilization and neutralization ofgauzy and liquid wastes. The closest analogue for this Nanodiamondrefinement method is one described in literature (Gubarevich T. M.,Dolmatov V. Y. Chemical refinement of diamonds by hydrogen peroxide.Applied Chemistry magazine. 1992, t. 65, No 11, p. 2512-2516). Themethod consists of treatment of detonation products, containingnanodiamonds, by oxidizing solution, including hydrogen peroxide, nitricacid or variable valency metal salt. This method disadvantage is in useof expensive and rare oxidizer—hydrogen peroxide, danger of operatingwith such easily decomposing combination, constantly emitting veryactive oxidizer—atomic oxygen.

SUMMARY OF THE INVENTION

The objective of the given invention is developing Nanodiamondproduction method-safe, reliable, characterized by improved technical,economical and ecological parameters and allowing to organize wideproduction of nanodiamonds, possessing predictable qualities andpredictable elemental composition with high carbon content in desiredphase conditions.

During invention development the objective was set to develop the methodof producing nanodiamond, possessing high concentration of carbon ofdesired modifications and desired phase composition from carbon-basematerial using detonation synthesis under conditions preventingoxidation of nanodiamond surface and providing safety of the acquireddiamond phase.

The objective was achieved through production of diamond-carbonmaterial, containing carbon, hydrogen, nitrogen and oxygen. Itsdistinction is that material contains carbon in form of diamond cubicmodification and in x-ray amorphous phase with ratio (82-95):(18-5)according to carbon mass, respectively, and contains, mass. %:

-   Carbon 90.2-98.0-   Hydrogen 0.1-5.0-   Nitrogen 1.5-3.0-   Oxygen 0.1-4.5

The objective was achieved through development of method of productionof nanodiamond, containing detonation of carbon-containing explosivewith negative oxygen balance in closed volume in gauzy environment inerttowards carbon, in condensed phase surrounding, distinguished bycarrying out detonation of carbon-containing material explosive put intocondensed phase cover, containing deoxidizer at quantitative ratio ofdeoxidizer mass in condensed phase to mass of the used carbon-containingexplosive not less than 0.01:1. Chemical refinement is applied bytreating detonation products by 2-40% water nitric acid alone withcompressed air oxygen at temperature of 200-280° C. and pressure 5-15MPa, and produce Nanodiamond, containing mass. % :

-   Carbon 90.2-98.0-   Hydrogen 0.1-5.0-   Nitrogen 1.5-3.0-   Oxygen 0.1-4.5    containing diamond cubic modification carbon and x-ray amorphous    phase carbon in ratio (82-95): (18-5) mass. %, respectively. It is    reasonable, according to invention, to use as deoxidizer organic or    inorganic compounds, preferably those not containing oxygen and    halogen atoms.

Further, the given invention is explained with help of examples of itsrealization, however, not limiting possibilities of the methodrealization and not stepping out the patent claims.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The process of nanodiamond formation by method according to invention,including detonation of carbon-containing explosive with negative oxygenbalance, surrounded by condensed phase containing deoxidizer can bedivided into four stages.

1. Stage one. Detonation transformation of carbon containing explosiveat blast mainly happens in range of charge volume, limited by its outersurfaces, but charge surrounding environment does not influence theprocess of transformation.

According to research results, explosive materials with negative oxygenbalance leads to creation of “extra” carbon, which remains in condensedform. Part of this “extra” carbon transfers into cubic modificationdiamond after explosion.

Charge placement into environment of liquid or solid aggregatecondition, e.g. when blown up in the pool filled with water or ice thatprevents detonation products throwout, creates conditions for increasedlength of existence of high pressure and temperature complex created atdetonation, which is existence environment for diamond and liquidcarbon.

Charge placement inside the condensed phase, both liquid or solidaggregate condition, containing cover, e.g. in form of ice or water,also allows to keep the detonation products for longer time in thevolume of primary charge, which leads to prolonged existence of plasma,containing detonation products, and contributes to better transformationof “extra” carbon into diamond phase.

2. Stage two. This transformation stage starts after the detonationprocess completes. It is very important to provide fast gas-dynamiccooling of detonation products for preservation of cubic modificationdiamonds, created in chemistry transformation zone. It is known that dueto explosion in vacuum, the fastest gas-dynamic cooling of detonationproducts takes place due to high speed of throwout. However, kineticenergy of detonation products transforms into heat energy as they blowthe walls of the explosive chamber. Chamber temperature goes up fastachieving very high values and after calming down of all blows insidethe chamber the temperature sets up for ˜3500 K—close to detonationtemperature. The cubic modification diamonds fully transform intographite, as chamber pressure drops times faster then chambertemperature. After that all CC gasify due to prolonged influence of hightemperatures that is why cubic modification diamonds do not preserver invacuum explosion. The slowest gas-dynamic cooling exists at detonationproducts throwout surrounded by massive ice or water covers. So maximumset temperature of detonation products does not exceed 500-800K due toeffective energy extraction by water (RU, 2230702, C; V. A. Mazanov.Macrokinetics of condensed carbon and detonation nanodiamondpreservation in hermetic explosive chamber, solid body physics, 2004, t.46, iss. 4, p. 614-620).

The gas-dynamic cooling intensity of explosion in inert gas environmenttakes middle value between vacuum explosion and condensed phase, in formof water or ice, cover explosion, as speed of detonation productsthrowout in gas environment is lower than in vacuum but higher than inwater and ice cover. As CC existence is determined mainly by residualtemperature in explosive chamber—the lower the temperature, the higherthe diamond-carbon material output—then the use of condensed coversaround the charge seems to be the best since they create the highestcooling rate.

3. Stage three of detonation synthesis of diamond-carbon material comesafter shock waves reflection from the chamber walls: circulation ofshock waves, spreading with supersonic speed and accompanied byprocesses of sharp increase of substance density, pressure andtemperature, and turbulent mixing of detonation products withenvironment inside the chamber takes place. The maximum set temperatureof environment inside the chamber depends on ration of explosive massand gas components, i.e. chemical environment activity and gases heatcapacity.

4. Stage four. The environment, heat by explosion of carbon-containingexplosive and limited by cool cover—is cooling intensively. Afterexplosion and detonation products release, chamber contains variouskinds of gauzy products (CO₂, CO, O₂, H₂, N₂, CH₄, NO, NO₂, NH₃, H₂O),and highly dispersed suspension of CC particles possessing high radiatecapability. Thus the process of such environmental cooling ischaracterized by combined heat transfer through convection and emission.

Using the method of electroconductivity profile measurement indetonation wave they determined that time of cubic diamond modificationformation does not exceed 0.2-0.5 mcs, which corresponds to the width ofchemical reaction zone in mix compositions of trinitrotoluene-cycloniteexplosions, both pressed and lithium (Staver A. M., Ershov A. P.,Lyamkin A. I. Research on detonation transformation of condensedexplosives by electroconductivity method. Physics of burn and explosion,1984 t. 20, Ks3, p. 79-82).

As part of substance formed in the first stage of detonation solid CCparticles transforms into gases under the influence of gauzy oxidizersformed by explosion: CO₂, H₂O, CO, O₂, N₂O₃, NO₂, we can talk aboutpreserved particles CC that didn't succeed to gasify, including due tolack of above mentioned oxidizers.

Any non responded solid particles of CC carbon have functional groupscover. Thus interaction of surface functional groups with gauzyoxidizers is capable to change primary functional groups, including nonoxygen containing for oxygen containing, as all oxidizers containoxygen. The use of important deoxidizer function—tie oxidizer,preventing carbon oxidation, creates conditions for preventing carbonparticles surfaces from oxidation. Thus, creating conditions forconsiderable increase of carbon content in nanodiamond. This increase isbeing achieved through decrease in oxygen content, as following researchresults, content of nitrogen and hydrogen changes insufficiently. Weshould also note the fact that high content of oxygen in nanodiamondsprevents it from efficient use in some technologies. For example, whenusing diamond-carbon material as additives to oil, availability of largequantity of oxygen increases oxidizing capability of material.

Maximum output of CC—12%—is achieved by explosion of carbon-containingmaterial in gas chamber under conditions of set temperature of1500±150K. Increasing the temperature in chamber till 3000-3500K we willdecrease the output till zero. (V. A. Mazanov. Macrokinetics ofcondensed carbon and detonation nanodiamond preservation in hermeticexplosive chamber, solid body physics, 2004, t. 46, iss. 4, p. 614-620).

Preservation possibility of received diamonds of cubic modification andelemental composition of diamond-carbon material depends on intensity ofhetero phase endothermic reactions of CC gasification by carbon dioxide(1) and water steam (2) behavior in gas chamber that can be presented assingle gross-reaction (3):

-   C+CO₂>2CO−172.4 kJ/mole (1)-   C+H₂O>CO+H₂−130.1 kJ/mole (2)-   C+CO₂+H₂O>3 CO+H₂−151.3 kJ/mole (3)

Two competing processes occur in explosive chamber under hightemperature:

CC gasification—non-diamond carbon in the first turn as more active, andgraphitization of formed diamonds of cubic modification.

Thus authors found it reasonable to develop conditions of synthesiscarrying out that would provide minimal influence possibilities ofdetonation products onto received, at detonation, product and maximumpossible speed of product cooling to prevent its gasification. Followinginvention, the input of deoxidizer into condensed cover of the chargeallows achieving several effects:

1. Deoxidizer prevents carbon particles surface from oxidation in thethird stage of detonation process, by tying oxidizers as the most active

chemical components inside the chamber. As a result, content of the mainheteroatom-oxygen, preventing farther use of CC, sharply drops till0.1%, and its place is taken by quite inert and neutral hydrogen. Carboncontent increases to 95.2%.

2. The chamber temperature drops sharply due to partial decomposition ofoxidizer under high temperatures, which in turn, decreases gasificationprocess (reactions 1-3) and “freezes” phase transformationdiamond-graphite.

Thus deoxidizer input allows increasing nanodiamonds output by 1.7-2.6times in comparison to nanodiamonds output 3.1-5.1% using knowntechnology (U.S. Pat. No. 5,681,459, A).

Any organic or inorganic compositions possessing deoxidizer qualities,mainly those not oxygen- and halogen-containing and showing expresseddeoxidizer qualities, can be used as deoxidizer. Intermediate product,produced as a result of detonation synthesis is highly dispersedcondensed carbon (CC), containing not only nanodiamonds, but alsonon-diamond carbon in high reactivity form, is undergoing chemicaltreatment according to invention. Nitric acid is quite powerful oxidizerfor non-diamond carbon. The interval used for nitric acid concentrationrefinement 2-40 mass. % was determined experimentally, according totechnologically acceptable speeds of reaction. Lowering concentrationbelow 2% leads to productivity decrease. Increasing nitric acidconcentration over 40% is unreasonable due to increased number of acidwaste and increasing corrosion activity of environment.

In case we treat CC by nitric acid with concentration of 2-40 mass. %only with all other technological conditions unchanged (t=200-280° C.and P=5-15 MPa), refinement quality will be very low and the purity ofproduced nanodiamond will not exceed 85%.

Using concentration of nitric acid 2 mass. % one should maintaintemperature 280° C., pressure 12-15 MPa due to compressed air (properpressure of 2% nitric acid is 6.5 MPa). Conditioning time—one hour.

The purity of produced nanodiamond—98.7%.

For 40% mass nitric acid it is enough to maintain temperature 200° C.and pressure 5 MPa due to compressed air (proper pressure of 40% nitricacid is 2.9 MPa). Conditioning time is 40 min. The purity of producednanodiamond 99.2%.

Compressed air secures surplus pressure and ultrabalanced oxygencontent, and also high speed of nitric acid regeneration in the system.The value of surplus pressure is 2-9 MPa, created by compressed air,secures both physical conditions (liquid-phase of the system) andcompacted material balance between gauzy and compensated components ofthe system. System's general pressure interval is 5-15 MPa isexperimentally determined field of process behavior. Compressed airinput into oxygen oxidation system creates the best conditions foroxidation process. Non-diamond carbon oxidation products—CO₂, NO₂,NO—evolve into gauzy phase. The processes of nitric acid regenerationbehave in the following scheme at simultaneous surplus of compressed airin solution and gauzy phase;

-   2 NO+O₂⇄2 NO₂⇄N₂O₄-   4 NO+3 O₂+2 H₂O⇄4 HNO₃-   4 NO₂+O₂+2 H₂O⇄4 HNO₃

Newly created nitric acid comes into reaction with non-diamond carbon.The oxidation system in question can also oxidate main non-carbonimpurities in CC—iron, copper, their oxides and some carbide. The giveninvention can be illustrated by examples of nanodiamond productionmethod realization according to invention, including method of condensedcarbon production and its following chemical treatment and production ofnanodiamond with improved qualities. Mixed carbon-containing explosivesare usually used for CC synthesis, e.g. mix of trinitrotoluene andhexogen or octogen with trinitrotoluene content from 30 to 70%. It isalso possible to use trinitrotriaminbenzol mixed with trinitrotoluene,hexogen or octogen. The following was chosen for tests of carboncontaining explosives:

-   -   charges from mix of trinitrotoluene and hexogen, formed by        pressing underpressure of 1500 kg/SM ² with ratio 50/50        (examples 1-18) and melting with ratio 65/35 (examples 19,20);    -   charges from mix of trinitrotoluene and octogen, formed by        pressing underpressure of 1500 kg/SM ² with ratio 60/40 (example        21);    -   charges from mix of trinitrotriaminbenzol and octogen, formed by        pressing under pressure of 1500 kg/SM ² with ratio 50/50        (example 22).

Traditional charge form was chosen—solid cylinder, and cylindricalcartridge diameter—48.5 mm. charge length—167.1 mm.

Charge blasting was realized using electrodetonator, located from thebutt end inside the charge. The charge of carbon-containing explosivewas put into condensed phase cover—solution of deoxidizer in water inliquid aggregate condition (examples 1-16,18,19,21,22) or in icecondition (example 20), or in cover produced as charge armor frompressed solid deoxidizer (example 17). The cover mass is from 4.0 to 6.0kg. The covers, in liquid aggregate conditions, were cylindricalpolyethylene bags, filled with condensed phase of deoxidizer solutionand charge, hanged inside the bag. In case of solid aggregate conditionof the cover with use of adamantan as deoxidizer, the cover looked likeouter armor over entire surface.

The following was used as deoxidizers: dimethylhydrazine (examples 1-5,19), urotropine (examples 6-10, 20-22), ammonia (examples 11-13),carbamide (examples 14-16), adamantan (example 17), acentonitrile(example 18) with different, in range of (0.01-10.0):1.0, correlation ofmass of used deoxidizer and mass of used explosive correspondingly.

The tests were carried out the following way: covered charge was placedinto explosive chamber through upper hatch. The explosive chamber ismade of stainless steel, volume of 1 m³, filled with gauzy products ofprevious blasting. The chamber was closed then and charge blasted. Inthree minutes after blast the unloading of received water suspension wasrealized through the lower valve into receiving capacity. Watersuspension then was passed through 200 mcm sell sieve and dried. Driedproduct was crushed and sifted through 80 mcm sell sieve and afterwardsthe samples of the received product were prepared for further researchof their elemental composition according to invention method.

Received product was put into titanic autoclave with 56% nitric acidwith estimation of 1 part of received product for 20 parts of acid.Autoclave was heated up to 513K and kept at this temperature for 30minutes. Then autoclave is cooled, gases were bled, product suspensionin work of weak nitric acid was retrieved. Nanodiamonds were washed indistillated water till pH 6-7 and air dried at temperature of 423K for 5hours.

Samples of the received product were prepared for further research oftheir elemental composition according to invention method. Researcheshave determined that diamond-carbon material contains from 8 to 14 mass% of volatile impurity (mainly water, nitrogen oxides and hydrogenoxides). Removal of such impurities, hardly tied by adsorptive forces inmicropore, by ordinary air heating at temperatures 120-125° C. isimpossible.

Heating temperature increase to higher temperatures is dangerous due todecomposition and flammability of particles of non diamond carbon. Tocompletely remove volatile impurities one should use vacuum withresidual pressure 0.01-10.0. The temperature should be maintained in therange of 120-140° C.

Temperature 120° C. is sufficient in vacuum 0.01 Pa, and 140° C. in 10.0Pa vacuum. It is unreasonable to maintain pressure less then 0.01 Pa dueto economical reasons, and higher then 10.0 Pa—due to possible notcomplete removal of volatile impurities. Increasing temperature beyond140° C. may cause decomposition of part of unstable non-diamond carbon.The heating time of 3-5 hours guarantees complete removal of volatileimpurities. Three hours is enough at 0.01 Pa and 120° C., whereas fivehours needed at 10.0 Pa and 140° C.

The standard methodology from organic chemistry is usually usedto-determine elemental composition of nanodiamond: heating temperaturein oxygen flow is 850-900 C during 5 s. However nanodiamond differs alot by its resistance towards oxidation from any organic compounds. Thusconditions stated above are not enough for complete oxidation of theelements forming nanodiamond. The temperature providing full oxidation(burn) of nanodiamond is 1050-1200° C., and heating time to be 40-50seconds. These conditions can be achieved using device No 185 of“Hewlett Packard” (USA).

Samples of received products were sustained at 120-140° C. temperaturein vacuum 0.01-10.0 Pa for 3-5 hours and undergo treatment by the oxygenflow under the temperature of 1050-1200° C. with speed providing itsburning for 40-50 sec.

Samples of synthesis products, prepared by method described aboveundergo the following tests:

-   -   Research using small-angle dispersion method for determination        of quantitative distribution of particles of material over its        size;    -   Research using polarographic titration for determination of        existence and composition of surface, oxygen-containing, amine        and amide functional groups. The amine, amide, hydroxyl,        carboxyl groups are identified by value of corresponding        reduction potentials and IR-spectroscopy data;    -   Research using gas-chromatographic analysis for existence of        surface throwing groups, identified by composition of emitted        gas at heating, at temperature 663-673K during 3 hours, per        quantity of emitted methane. The achieved products were heated        at 473K in vacuum (0.1 Pa) until achieving the product of        constant weight (during 24 hours) before gas-chromatographic        analysis. During the heating process previously absorbed by        received product surface volatile products, including gases,        were eliminated, and emitted at gas-chromatographic analysis        gases CH₄, H₂, CO₂, CO, O₂, N₂ and NH₃ were gases forming at        destruction of chemically connected with CC surface groups;    -   Research using x-ray photoelectron spectroscopy (XPES) to        analyze the distribution of carbon forms in achieved product;    -   Research using small-angle dispersion method (Svergoon D. I.,        Feigin L. A. x-ray and neutron small-angle dispersion, Moscow,        izd <<Nauka>>, 1986, 280 p);    -   Research using determination of specific surface using powder        means of low-temperature sorption nitrogen method (further BET)        (Gerasimov Y. M. and others. Physical Chemistry. T. I, edition        2., Moscow, izd. <<Chemistry>>, 1969, p. 592).

Research results are shown in Table.

TABLE Production of nanodiamond according to invention by the means ofinvention Acquisition method Example No. components Item Parameters 1 23 A. Explosive 1 Composition Trinitrotoluol/ Trinitrotoluol/Trinitrotoluol/ hexogene, 50/50, hexogene, 50/50, hexogene, 50/50,pressed pressed pressed 2 Massa, kg 0.5 0.5 0.5 3 Density, g/cm³ 1.621.62 1.62 B. Shell 4 Deoxidant dimethylhydrazine dimethylhydrazinedimethylhydrazine 5 Weight ratio of the 0.32:1.00 0.01:1.00 0.16:1.0deoxidant to the water explosive liquid 6 Solvent water water 4.0 7Shell aggregate state liquid liquid 9.5 8 Massa, kg 4.0 4.0 C. Derived 9Nanodiamond output, 9.1 7.0 product % of the explosives 10 Elementcomposition, mass %: [C] 96.1 90.2 93.9 [H] 1.0 5.0 1.6 [N] 2.2 1.5 2.5[O] 0.4 3.2 1.2 Nonflammable 0.3 0.1 0.8 impurities 11 Nanodiamond phasecomposition, mass %: cubic diamond, 91 85 88 X-ray amorphous 9 15 12carbon phase 12 Nanodiamond content 60.0 58.0 68.0 in CC Acquisitionmethod Example No. components Item Parameters 4 5 6 A. Explosive 1Composition Trinitrotoluol/ Trinitrotoluol/ Trinitrotoluol/ hexogene,50/50, hexogene, 50/50, hexogene, 50/50, pressed pressed pressed 2Massa, kg 0.5 0.5 0.5 3 Density, g/cm³ 1.62 1.62 1.62 B. Shell 4Deoxidant dimethylhydrazine dimethylhydrazine urotropine 5 Weight ratioof the 0.64:1.00 10.0:1.00 0.01:1.00 deoxidant to the explosive 6Solvent water water water 7 Shell aggregate state liquid liquid liquid 8Massa, kg 4.0 4.0 6.0 C. Derived 9 Nanodiamond output, 10.1 8.6 8.3product % of the explosives 10 Element composition, mass %: [C] 94.298.0 92.3 [H] 2.9 1.1 2.1 [N] 2.9 1.7 2.3 [O] 0.1 0.1 1.8 Nonflammable0.9 0.1 1.5 impurities 11 Nanodiamond phase composition, mass %: cubicdiamond, 91 95 86 X-ray amorphous 9 5 14 carbon phase 12 Nanodiamondcontent 63 61 66 in CC Acquisition method Example No. components ItemParameters 7 8 9 A. Explosive 1 Composition Trinitrotoluol/Trinitrotoluol/ Trinitrotoluol/ hexogene, 50/50, hexogene, 50/50,hexogene, 50/50, pressed pressed pressed 2 Massa, kg 0.5 0.5 0.5 3Density, g/cm³ 1.62 1.62 1.62 B. Shell 4 Deoxidant urotropine urotropineurotropine 5 Weight ratio of the 0.25:1.0 0.50:1.00 1.0:1.0 deoxidant tothe explosive 6 Solvent water water water 7 Shell aggregate state liquidliquid liquid 8 Massa, kg 6.0 6.0 6.0 C. Derived 9 Nanodiamond output,10.4 11.5 12.0 product % of the explosives 10 Element composition, mass%: [C] 94.9 95.2 96.0 [H] 1.1 1.0 0.4 [N] 2.5 2.2 2.6 [O] 1.4 1.5 0.7Nonflammable 0.1 0.1 0.3 impurities 11 Nanodiamond phase composition,mass %: cubic diamond, 90 92 91 X-ray amorphous 10 8 9 carbon phase 12Nanodiamond content 71 74 75 in CC Acquisition method Example No.components Item Parameters 10 11 12 A. Explosive 1 CompositionTrinitrotoluol/ Trinitrotoluol/ Trinitrotoluol/ hexogene, 50/50,hexogene, 50/50, hexogene, 50/50, pressed pressed pressed 2 Massa, kg0.5 0.5 0.5 3 Density, g/cm³ 1.62 1.62 1.62 B. Shell 4 Deoxidanturotropine ammonia ammonia 5 Weight ratio of the 10.0:1.00 0.01:1.00.50:1.00 deoxidant to the explosive 6 Solvent water water water 7 Shellaggregate state suspension liquid liquid 8 Massa, kg 6.0 5.0 5.0 C.Derived 9 Nanodiamond output, 11.2 6.0 6.8 product % of the explosives10 Element composition, mass %: [C] 97.0 91.4 92.7 [H] 0.7 2.9 2.4 [N]2.0 2.8 2.9 [O] 0.1 2.0 1.3 Nonflammable 0.7 0.9 0.7 impurities 11Nanodiamond phase composition, mass %: cubic diamond, 95 86 89 X-rayamorphous 5 14 11 carbon phase 12 Nanodiamond content 69 52 51 in CCAcquisition method Example No. components Item Parameters 13 14 15 A.Explosive 1 Composition Trinitrotoluol/ Trinitrotoluol/ Trinitrotoluol/hexogene, 50/50, hexogene, 50/50, hexogene, 50/50, pressed pressedpressed 2 Massa, kg 0.5 0.5 0.5 3 Density, g/cm³ 1.62 1.62 1.62 B. Shell4 Deoxidant ammonia carbamide carbamide 5 Weight ratio of the 1.0:1.010.0:1.00 0.4:1.0 deoxidant to the explosive 6 Solvent water water water7 Shell aggregate state liquid liquid liquid 8 Massa, kg 5.0 5.0 5.0 C.Derived 9 Nanodiamond output, 6.4 7.5 9.0 product % of the explosives 10Element composition, mass %: [C] 92.1 92.8 91.6 [H] 2.9 1.8 1.8 [N] 3.02.2 2.5 [O] 1.2 2.1 3.0 Nonflammable 0.8 1.1 1.1 impurities 11Nanodiamond phase composition, mass %: cubic diamond, 91 88 86 X-rayamorphous 9 12 14 carbon phase 12 Nanodiamond content 49 58 61 in CCAcquisition method Example No. components Item Parameters 16 17 18 A.Explosive 1 Composition Trinitrotoluol/ Trinitrotoluol/ Trinitrotoluol/hexogene, 50/50, hexogene, 50/50, hexogene, 50/50, pressed pressedpressed 2 Massa, kg 0.5 0.5 0.5 3 Density, g/cm³ 1.62 1.62 1.62 B. Shell4 Deoxidant carbamide adamantane acetonitrile 5 Weight ratio of the10.0:1.00 1.4:1.0 2.0:1.00 deoxidant to the explosive 6 Solvent water —water 7 Shell aggregate state liquid pressed liquid solid 8 Massa, kg5.0 charge inhibitor 5.0 C. Derived 9 Nanodiamond output, 5.4 12.6 8.0product % of the explosives 10 Element composition, mass %: [C] 90.897.2 95.3 [H] 1.4 0.2 1.2 [N] 3.0 2.1 2.2 [O] 4.5 0.2 0.9 Nonflammable0.3 0.3 0.4 impurities 11 Nanodiamond phase composition, mass %: cubicdiamond, 85 95 93 X-ray amorphous 15 5 7 carbon phase 12 Nanodiamondcontent 40 80 56 in CC Acquisition method Example No. components ItemParameters 19 20 21 A. Explosive 1 Composition Trinitrotoluol/Trinitrotoluol/ Trinitrotoluol/ hexogene, 65/35, hexogene, 65/35,octogene, 60/40, melted melted pressed 2 Massa, kg 0.51 ~0.51 ~0.51 3Density, g/cm³ 1.64 1.64 1.65 B. Shell 4 Deoxidant dimethylhydrazineurotropine urotropine 5 Weight ratio of the 0.64:1.0 0.5:1.0 0.5:1.0deoxidant to the explosive 6 Solvent water water water 7 Shell aggregatestate liquid ice liquid 8 Massa, kg 4.0 6.0 6.0 C. Derived 9 Nanodiamondoutput, 11.7 12.9 13.3 product % of the explosives 10 Elementcomposition, mass %: [C] 94.8 95.2 95.9 [H] 1.2 1.1 0.2 [N] 2.9 2.0 2.1[O] 0.2 1.1 0.8 Nonflammable 0.9 0.6 1.0 impurities 11 Nanodiamond phasecomposition, mass %: cubic diamond, 92 94 93 X-ray amorphous 8 6 7carbon phase 12 Nanodiamond content 69 78 79 in CC Acquisition methodExample No. components Item Parameters 22 A. Explosive 1 CompositionTriaminotrinitrobenzol/ octogene, 50/50, pressed 2 Massa, kg 0.53 3Density, g/cm³ 1.71 B. Shell 4 Deoxidant urotropine 5 Weight ratio ofthe 0.5:1.0 deoxidant to the explosive 6 Solvent water 7 Shell aggregatestate liquid 8 Massa, kg 6.0 C. Derived 9 Nanodiamond output, 6.8product % of the explosives 10 Element composition, mass %: [C] 92.0 [H]2.3 [N] 2.6 [O] 2.3 Nonflammable 0.8 impurities 11 Nanodiamond phasecomposition, mass %: cubic diamond, 86 X-ray amorphous 14 carbon phase12 Nanodiamond content 52 in CC

Researches have discovered that nanodiamond, produced by method ofinvention is powder from light grey to grey color. Based onpolarographic, chromatographic and IR-spectroscopic analysis, thestructure of surface functional groups was determined: hydroxyl,carboxyl, carbonyl, amide, nitric, and methane groups were discovered inall samples received in the process carried out according to invention.

X-ray pictures of nanodiamond (Cu K_(α)), produced by mentioned method,show wide symmetrical, well described by Lorenzo's counters diffractionmaximums at angles of 2Θ=43.9, 75.3 and 91.5° corresponding to (111)-,(220)- and (311)-reflections from the grid of cubic modificationnanodiamond with grid parameter a_(o)=3.565±0.002 A.

Average size of produced nanoparticles—4.0-5.0 nm indicates thatwidening of diffraction maximums is mainly connected to small particlessize, not internal tension.

Strong allocated halo is observed in the range 2Θ=16° -37° that typicalfor diffraction on random amorphous structures, confirming the presenceof x-ray amorphous carbon phase. This structures thickness estimation onhalo half-width is 2-4 Å, that is 5-18 mass. % from nanodiamond weight.Besides quantity of amorphous phase was determined from decrease inreflection intensity till 220 nanodiamond according to given inventionin comparison to sample of pure natural cubic diamond (Yakutia-Sakha,set. Mirnyi, Russian Federation). X-ray amorphous phase estimatedquality is from 5 to 18 mass. %. Existence of ˜2.5 mass. % nitrogen inamorphous phase is determined as follows.

Nanodiamond hinged, produced by method according to given invention, washeated at 473K for 20 hours in vacuum in 0.1 Pa until constant weight.Then, different parts of this hinge undergo deep extraction by variousdissolvents at temperature of 473-573K under pressure during 3 minutes.Dissolvent used: normal structure—heptane, decane; aromatic-benzol,toluol, alicyclic-cyclohexanecarbon; hydro-naphthalene-tetralyne anddecalyne. The ratio of diamond phase of carbon, which does not changeunder such conditions, and amorphous phase, which has decreased, aftersuch treatment was changed. Nanodiamond samples weight has lowered for˜5 mass. %. Only nitrogen-bearing heterocyclic aromatic compositionswith number of cycles from 1 to 4 and nitrogen content in circles 1-2have passed into solution of above mentioned dissolvents. No otherheteroatom in any form was found in solution. IR-specters have shown innanodiamond after extraction all the same surface oxygen, hydrogen,nitrogen-containing groupings placed there before extraction. Thus,nitrogen in form of heterocyclic compositions was definitely suppliedfrom middle layer—x-ray amorphous phase of carbon.

Moreover, complicacy of x-ray amorphous phase of carbon structure innanodiamond demonstrates the fact that when similarly nanodiamondssamples according to invention (mode: 473K, 20 hours, 0.1 Pa) undergothermal desorption under sift conditions (mode: 573K, 2 hours, 0.001Pa), desorption products content was diverse: acentonitrile,nitromethane, butanone-1 -on and butanone-2 -on, tetrahydrofuran,ethilazitate, benzol and homolog, alkyl benzene (C₉ and C₁₀), alkanes(C₇-C₁₁), ethylene (C₇-C₁₀), terpene (C₁₀) and naphthalene (C₁₀).

Partial destruction of outer functional groups takes place at 573K.During this process nitromethane, butanone, tetrahydrofuran, ethylatite,presumably, acentonitrile. However main quantity of identifiedcompositions: benzol and homolog, alkanes, alkenes, terpene andnaphthalene—possessing special character and structure, may form only atx-ray amorphous carbon phase destruction that is verified by fact ofsamples mass reduction after thermal desorption ˜8 mass. %. Temperatureof nanodiamonds oxidations beginning in open air-gasificationtemperature, measured by derivathograph at heating speed 10 deg/min, is473K, and small exo-effect is observed till 800 K. All non-diamond x-rayamorphous carbon is being oxidated at this. The sample weight reductionis 5-18 mass. %, corresponding with x-ray carbon quantity innano-diamond.

After heating over 800K strong exo-effect is observed. This testifiesabout reaction of air oxygen with diamond nuclei of nano-diamond that isover at 1050K by nanodiamond full oxidation (burning out). Maximum heatdischarge (maximum oxidation) takes place at 930-990K.

The research of crystal diamonds of static synthesis (ASM), smashed intoparticles 2-100 nm in size (with average diameter of 20 nm), put intoconditions alike, were carried out. Research showed that the temperatureof the diamond crystal oxidation process beginning is 785K, but maximumoxidation temperature is 890K. Full oxidation process of ASM is over at1060K. So, oxidation resistance of classic diamond and nanodiamond,according to given invention, and classic synthetic diamonds is almostthe same.

Nanodiamond, produced by method according to closest analogue, has itsdiamond nuclei oxidated at 703K.

Every particle of nanodiamond of given invention has complicatedstructural formation, including the following elements as compulsorycomponents:

-   carbon atoms nuclei sp³-hybridized, connected into cubic crystal    structure, typical for diamonds; nuclei covers 82-95% of carbon    atoms and possesses due to x-ray-graphy size of 40-50 Å; nuclei has    ˜2.5 mas. % nitrogen, mainly in form of substitution atoms;    transition carbon cover around the nuclei, consisting from x-ray    amorphous structures of carbon with width of 2-4 Å, which can    contain 5-18% of carbon atoms of a particle. The cover, consisting    of carbon in sp²-hybridization, is not uniform. Internal layer of    this cover, directly adjoining nuclei, form continuous onion-like    carbon layers, fragmented, graphite-like layers (aromatic clusters)    located above them.

This amorphous carbon cover possesses porous structure, various defects,includes small quantity of heteroatoms (first of all—2.5 mass. %nitrogen), enter the cover structure in process of detonation synthesis;

-   surface layers, containing other heteroatoms except carbon atoms,    forming specter of different functional groups (hydroxyl-,    carbonyl-, carboxyl, nitrile and methal groups). Overall quantity of    heteroatoms in particle—nitrogen, hydrogen and oxygen—is from 2.0 to    9.8 mass, %.

Thus, it was determined that nanodiamonds are not pure carbon material.Carbon exists in the product simultaneously in different modificationsand only one of them corresponds to diamond structure. Outer cover ofnanodiamond particle determines its relation with the environment. Thatis it forms the phase interface and takes part in interacting with it.Presence on the surface of highly-polar and reaction-capable groupings,concentrated in small volume, determines sufficient influence activityof nanodiamond particles onto environment.

Nanodiamond, produced by present invention, is unique material due toits transitional nature from inorganic product to organic and thisdetermines its special position among ultradispersed materials.

Industrial use.

Nanodiamond, produced by method according to invention, allows its useas nanosize component of high-efficacy composite materials as additives,improving exploitation characteristics of construction-endurance,durability, resource—more than from use of nanodiamonds, known fromabove described previous technical level. Nanodiamonds, according toinvention, can be produced by method according to invention, which canbe realized with help of existing technological equipment and knownexplosives.

1. Nanodiamond comprising carbon, hydrogen, nitrogen and oxygen wherein the carbon is diamond cubic modification and x-ray amorphous phase carbon with a ratio (82-95):(18-5) mass % of carbon mass, respectively, and comprising mass %: Carbon 91.0-98.0 Hydrogen 0.1-5.0 Nitrogen 1.5-3.0, and Oxygen 0.1-4.5 and wherein the nanodiamond has been prepared by detonating carbon-containing explosive with negative oxygen balance in closed volume and in gaseous environment being inert towards carbon, surrounding charge of explosive with by condensed phase containing required amount of deoxidizer a mass ratio of the deoxidizer in the condensed phase to a mass of used carbon-containing explosive not less than 0.01:1 respectively, chemically refining by treating formed products with 2-40% aqueous nitric acid along with compressed air oxygen at 200-280° C. and pressure 5-15 MPa.
 2. Nanodiamond production method comprising: detonating carbon-containing explosive with negative oxygen balance in closed volume and in gaseous environment being inert towards carbon, surrounding charge of explosive with by condensed phase containing required amount of deoxidizer a mass ratio of the deoxidizer in the condensed phase to a mass of used carbon-containing explosive not less than 0.01:1 respectively, chemically refining by treating formed products with 2-40% aqueous nitric acid along with compressed air oxygen at 200-280° C. and pressure 5-15 MPa, and producing nanodiamond containing mass %: Carbon 91.0-98.0 Hydrogen 0.1-5.0 Nitrogen 1.5-3.0 Oxygen 0.1-4.5, and containing carbon of diamond cubic modification and carbon in x-ray amorphous phase with ratio of (82-95):(18-5) mass %, respectively.
 3. The method of claim 2, wherein inorganic or organic substance is used as deoxidizer.
 4. The method of claim 3, wherein the deoxidizer does not contain elements selected from the group consisting of oxygen, halogen, and combinations thereof. 